Inhalation as a gentle therapeutic method is of great importance today, primarily in the field of disorders of the respiratory passages, or for simple and fast-acting administration of medicinal drugs. A dry powder treated with medicinal drugs may be supplied to the patient's respiratory passages as a fine mist. The method of delivery during inhalation requires a complete and uniform distribution of the dry powder that is uncomplicated and rapid.
German Patent Application 199 48 289.6 discloses an apparatus that makes possible such a distribution of the dry powder by the flow-controlling structure of a simple cylindrical body in a special inhalation housing. The air guide unit disclosed is in the form of a cylindrical body, surrounded by a housing, and is not flexibly replaceable. The dry powder must be fed to a special supply chamber, before its delivery to the air guide unit. To guarantee exact dosage of the dry powder and to ensure that the dry powder does not pick up any moisture, considerable technical outlay is required of the user.
U.S. Pat. No. 5,562,918 discloses a dispenser system for the inhalation of powdered medicinal drugs by suction using respiratory air. This dispenser consists of several parts, specifically a cylindrical main body comprising closures openable by action of axial force and is provided with an intake opening and an air inlet. To achieve an adequate turbulence of the air drawn in by the dispenser, a turbine is provided in the air inlet. In the nozzle, a grid is further provided, to prevent intake of larger particles.
The dispenser disclosed in U.S. Pat. No. 5,562,918 exhibits a complicated structure, rendering it costly to produce and complicated to use. The dispenser is limited in that two or more dispensers cannot be connected to each other magazine-fashion. Although it is a prerequisite for inhalation of all powder uniformly distributed in the air, the adequate turbulence of the air taken in by the dispenser is not to be expected through the use of the disclosed dispenser.
WO A 96/22802 shows an inhaler comprising a tubular body to define an air passage, provided with closure caps and filled with a powder. The air passage may be rectangular, square, polygonal, elliptical or circular in cross-section, the cross-sectional area being smaller at the nozzle than at the opposed end. In addition, flexible segments are provided to permit adaptation to anatomical givens. In order to improve the distribution of the particles being inhaled, the inhaler may be provided with means to generate a rotation of the air. Such means may comprise spiraled depressions or ribs on the inner wall of the tubular body. This inhaler, in the simplest embodiment, is of very simple structure, but fails to achieve an adequate turbulence of the air.
An inhalation device for delivery of dry powders must be simple to use and readily available at a moment's notice. Therefore, there is a need to minimize problems by simplifying the technical structure of the inhalation device.
The object of the invention, then, is to create an inhalation device affording access in a matter of seconds by immediate readiness for use, and by a structural reduction of the elements of the device, limiting to a minimum the operating moves of the patient before, during and after the inhalation, and likewise structurally ruling out virtually any risk of trouble.